Extreme pressure lubricant



Patented May 5, 1942 v UNITED STAT ES PATENT OFFICE ax'rnnm: ra'nssmmLonalcan'r na Egan-rill, Long n 3, Calif., assignor a on Comm! ornia,Los Ange Calif., a corporation of California I,

No Drawing. A plicatlon January 3, 1940, Serial No. 312,227

14 Claims.

- This invention relates to lubricants and par ticularly to extremepressure lubricating oils.

This is a continuation-in-part of my earlier application, Serial No.745,169, filed September 22,

1934. The primary object of the invention is to develop lubricants forsevere pressure operating uses which will be stable, free from acid, andat the same time possess the necessary high loadcarryingcharacteristics. Heretofore sulfur chlorinated oils such as thoseobtained by treatment of mineral oils and fatty oils with sulfurchloride have been employed as extreme pressure bases for addition tomineral lubricating oils, but these I have not been satisfactory for thereason that they have been unstable and usually could not be entirelyfreed from mineral acid, inasmuch as hydrogen chloride is usuallydeveloped at comparatively low temperatures. I have discovered, however,that various mineral oil fractions can be directly chlorinated bycontact with chlorine gas so as to produce substantially stable,acidfree chlorinated derivatives which may be added to lubricating oilsto impart to said lubricating oils the characteristics necessary toadapt them especially to extreme pressure or high load-carrying uses.

The invention therefore may be stated as residing in chlorinatedpetroleum fractions to be used as extreme pressure bases in thepreparation of extreme pressure lubricants, wherein the chlorine ischemically combined with a normally non-.volatile mineral oil fraction,as by direct contact of chlorine gas with the fraction. The inventionincludes also the lubricant wherein a quantity of mineral lubricatingoil or the like contains such a chlorinated petroleum fraction. Theinvention resides also in a method of producing lubricants of the statedcharacter, the

chlorination being accomplished by direct contact of the free chlorinewith the fraction being treated. The invention refers particularly tothe tion is carried. Where such more parafllnic oils,

as for example waxy lubricating dlstillates, are chlorinated withdifficulty, iodine or other catalystls may be added, as in chlorinatiohsin genera Considering the invention in greater detail, I

have discovered that any normally non-volatile petroleum fraction may bechlorinated by direct contact of chlorine gas with the fraction toproduce chlorinated products whose chlorine content will vary with thetime and conditions of chlorination. While straight run lubricating oilsmay be employed as the stock to be chlorinated, I have discovered thataromatic petroleum frac tions are more-susceptible to'chlorination thanthe non-aromatics. For example, cracked gasoline, cracked cycle stocks,j cracked residuums and products from the cracking of highly naphtheniccrude oils may be employed. Likewise, the extract obtained by the use ofliquid sulfur dioxide and similar solvents such as, sulfur dioxidefurand benzene, BB dichlorethyl ether, phenol, an-- iline, nitrobenzene,cresol and furfural, are especially suitable, for chlorination toproduce the extreme pressure bases of this invention. The llqfurcontents ranging ordinarily from about .25%

chlorination of aromatic fractions such as the fraction soluble inliquid sulfur dioxide and commonly known as "Edeleanu Extract andtofractions derived from cracking operations such as cracked gas line,cycle stock, cracked residuum,

and the various fractions from highly naphthenic crude oils, these beingparticularly susceptible to chlorination. However, oils oi more paramniccharacter may also be employed for chlorination, at least for some uses,the permissible extent of dilution however with an ordinary lubricatingoil usually being not so great, although this will I also vary with theextent to which the chlorina- 55 be greatly increased, for example. toas high as to about 3% or 4%, an average kerosene extract being about1.25%. These facts are common knowledge in the industry. The waxylubricating distillates are of course open-chain compounds. 1 i

Any of these materials may be chlorinated to produce a varying chlorinecontent, for example, from 5 or to hr chlorine, and the resultantchlorinated material added to mineral luadded to anysuitable lubricatingstock from either Eastern or-Westem oils or blends thereof, or thepercentage may be decreased, or it may 40 or sea, depending upon thedegree of chicrination. or the chlorinated bases and the degree ofextreme pressure characteristics required.

@hlorination may be readily efiected in any suitable type of protectedapparatus such as leadlined or glass equipment, the chlorine in gaseousform being bubbled through the material to be treated at. any desiredrate and under any condition adequate to produce thorough contact sothat a desired percentage of chlorine may be combined chemically withthe fraction under treatment. Iodine or other catalysts may be employedwhere necessary or desirable, for example where the more paramnic oilssuch as waxy lubricating distillates are otherwise chlorinated withdimculty.

As an example, Edeleanu extract obtained from a kerosene or lubricatingoil fraction by treat= ment with liquid sulfur dioxide to obtain theextract in the liquid sulfur dioxide which is then expelled from theextract, may be treated in apparatus such as above described by bubblinggaseous chlorine therethrough for a period of iii to so hours at atemperature of about 140 F. or between about 120 F. and ice i Theresultant chlorinated material is then washed with dilute alkali toremove hydrogen chloride and decompose any very reactive or unstablechlorinederivatives, thereby leaving only those chlorine derivativeswhich are at least moderately stable toward hydrolysis. Vigoroustreatment with alkali is ordinarily avoided. Instead of treatment withatkali, the reaction product may be merely washed with water, preferablywith'open steam agitation, and/or treated with decolorizing clays attemperatures of for example ec F. to too F. This chlorinated product isthen ready for addition to any of the previously mentioned lubricatingoils in whatever percentage may be desired for a given use as hereinindicated.

Chlorinated Edeleanu extracts as above. described are ordinarilyentirely soluble in Western or naphthenic base lubricating oils,inasmuch as these oils have good solvent properties for the chlorinatedproducts. Such lubricating oils are the typical naphthenic or asphalticbase type such as California lubricating oils and the like. For example,a California lubricating oil from a naphthenic base crude having aviscosity of 110 seconds Saybolt Universal at 210 F. has beensatisfactorily employed where using a chlorinated Edeleanu extract fromkerosene. In some instances, however, small quantities of sludgeformingmaterials or materials insoluble in lubricating oil and also insolublein the batch being chlorinated are sometimes developed in thechlorination operation, and in those instances, if these insolublematerials are objectionable, their formation may be avoided by givingthe Edeleanu extract a light acid treatment with strong acid beforechlorination, as with sulfuric, strong sulfonic, chlor-acetic andsulfamic acids. Again,

highly paraflinic lubricating oils sometimes have poor solvent power forchlorinated Edeleanu extracts or portions thereof, and this difllcultymay also be overcome by giving the Edeleanu extract an acid treatmentbefore chlorination. For example, I have given an Edeleanu extract fromkerosene a satisfactory treatment by agitation with about pounds of 98%sulfuric acid per barrelof 42 gallons. This amounts to about 3% and isclassed as a light acid treatment. Depending upon the nature of theEdeleanu extract and its tendency upon chlorination to developoil-insoluble materials or materials insoluble in the Ill 2' accruesbatch undergoing chlorination, the treatment may vary from 4 lb. or 5lb. of 98% sulfuric acid per barrel to perhaps 12 lb. to 15 lb. perbarrel of 42 gallons. in other words, the range is between about 1.5%and about 5% of 98% sulfuric acid.

The acid and sludge are then removed from the treated extract. Uponchlorination of the Edeleanu extract so acid treated, even when treatingat temperatures as high as about 200 l t, no

materials are developed which are insoluble in.

Westem oil, and likewise they are usually completely soluble in Easternor parafinic oils. Another advantage in acid treating the extract before.chlorination is that chlorination may then be extended from or to ashigh as or without interfering with the compatibil ity of the product inthemineral lubricating oil selected.

This is in addition to the fact that the mmperature range may beextended to lie between'about F. and 200 bi, although in general adesir= able average operating temperature is probably about 352- A As inthe case of the chlorinated non-acidtreated Edeleanu extract, theproduct may be water-washed and washedwith dilute alkali such thecaustic soda, and where there are tendencies towards emulsificationthese may be avoided in various ways as by using stronger caustic solution rather than weaker solution or by chlorinat= ing the product to alower degree for example 10% to 15% chlorine content, or by employing afortified spent alkali solution, or in other ways known to the petroleumchemist. For purposes of clarification the washed chlorinated materialmay be heated with 5% to 10% of any appropriate decolorizing clay, andfollowed by filtration. These chlorinated materials from acidtreatedEdeleanu extract are soluble to the required extent in both Eastern andWestern oils,

.- and exhibit suitable extreme pressure properties.

For example, various oils containing 12% of chlorinated extracts havingchlorine contents of from 15% to 35% have shown a load-carrying capacitywithout scoring of 50 lb. to 100 lb. on the Timken lubricant and weartester.

Chlorination can also be accomplished in the vapor phase, the chlorinegas being mingled with the vaporized fraction to be treated, and theresultant materials subsequently condensed. To obtain the necessaryvaporization without the use of temperatures at which the reaction wouldbe too vigorous the operation may be carried on at reduced pressureand/or with a carrier gas such as nitrogen or steam. Not only may thesechlorinated products be added to mineral lubricating oils and the like,but such oils may in turn be thickened with soaps such as calcium,sodium and aluminum soaps to form extreme pressure greases. Thus, bythis invention either mineral lubricating oil stocks or lubricatinggreases are produced containing chlorine inchemical combination withnormally non volatile mineral oils, these products all having extremepressure characteristics especially desirable for lubrication underheavy loads.

Such extreme pressure service includes not only gear lubricants forconditions of high tooth pressure, but also cutting oils and penetratingoils. In order to increase the oiliness of any of these oils which areto be used at times under intermediate pressure conditions. requiringthe characteristics of high oiliness, fatty oils and/or fatty or otheroil-soluble organic acids may be included in the composition containingthe mineral oil and chlorinated oil. In some instances such iatty oilsor acids could be used with the chlorinated oil to the exclusion of saidmineral oil. It is also within the scope of this invention to producemiscible oils for cutting, drawing, or other metal working operations,in which high film strength is desirable, by the inclusion in thecomposition containing the chlorinated compounds suitable emulsifyingagents, such as soaps and common solvents such as various alcoholsaswell known in the art, to make the composition readily orspontaneously emulsifiable in water.

It is to be understood that anyof the, various fractions hereindescribed may be chlorinated in any manner similar to that described,and may lubricant.

3. A lubricant comprising chlorinated Edeleanu extract.

i. A lubricant comprising Edeleanu extract "having between about and 45%of chlorine chemically combined therewith.

5. A lubricant comprising Edeleanu extract having a chlorine chemicallycombined therewith exceedingabout 10% of the extract.

6. A lubricant comprising a mineral lubricating 011 containing an amountsuflicient to impart extreme pressure characteristics thereto of lightlyacid-treated Edeleanu extract having chlorine chemically combinedtherewith.

7. A mineral lubricating oil containing an amount sumcient to impartextreme pressure characteristics thereto of chlorinated acidtreatedEdeleanu extract. v

8. A mineral lubricating oil containing an amount sufficient to impartextreme pressure characteristics thereto of chlorinated Edeleanu extractwhich has previously been treated with between about 1.5% and 5% of 98%sulfuric sure lubricant base comprising treating Edeleanu extract withabout 1.5% to 5% of sulfuric acid having aconcentration in the order of98%, removing the acid and sludge from the extract, chlorinating theacid-treated extract to cause the chemical combination of chlorine withthe extract to impart good extreme pressure-properties, and washing thechlorinated extract to remove unstable materials.

13. A method according to claim 12 and the additional step ofcommingling a minor proportion of said chlorinated extract with mineralubricating oil.

14. A method of producing an extreme pressure lubricant base comprisingtreating Edeleanu extract to remove constituents which would formsludgeor oil-insoluble materials, and chlorinating the treated extractto cause chemical combination of chlorine therewith and impart extremepressure properties.

DAVID R. MERRILL.

